Diversity Of Ground-dwelling Arthropods Research Articles

Effects of Different Tillage Years on Soil Composition and Ground-Dwelling Arthropod Diversity in Gravel-Sand Mulching Watermelon Fields

Arthropods play a crucial role in ecological processes and agricultural productivity. Soil physicochemical properties, indicators of soil health, are closely linked to arthropod communities. Gravel-sand mulching, commonly employed in arid farming, initially enhances water retention and temperature regulation but may contribute to land degradation with prolonged use. This study investigated how varying tillage durations affected soil properties and arthropod diversity under gravel-sand mulching. The analysis employed multiple comparison methods, covariance analysis (ANCOVA), non-metric multidimensional scaling (NMDS), and redundancy analysis (RDA). The results indicated that while soil fertility was better preserved in cultivated fields compared to in the desert grassland, arthropod diversity significantly decreased with longer cultivation periods. A total of 1099 arthropods from 79 species were sampled, by Barber trap. The highest diversity was observed in native grassland (NG), with 305 arthropods from 39 species, while tillage 21 years (GPS-21Y) exhibited the lowest diversity, with only 103 arthropods from 6 species. Dominant species included the carnivores Labidura japonica and Cataglyphis aenes. The analysis revealed low similarity in arthropod communities between GPS-21Y and other fields and high similarity in soil physicochemical properties between NG and the transition zone (STZ). RDA showed available potassium (APP) was negatively correlated with arthropod species diversity and concentration, total Nitrogen (TN) was positively correlated with arthropod species diversity but negatively correlated with species concentration, total phosphorus (TP) was negatively correlated with arthropod species diversity and concentration. This study provides insights into the relationship between maintaining soil fertility and supporting arthropod diversity in grassland agriculture. While soil fertility and arthropod diversity were correlated, continuous cropping practices negatively impacted arthropod diversity, offering valuable information for pest management and sustainable agricultural practices.

Sown Covers Enhance the Diversity and Abundance of Ground-Dwelling Predators in Mediterranean Pear Orchards

Intensive agriculture has a strong impact on the structure of arthropod communities in soil. Sown covers can contribute to their conservation, especially for generalist predators such as spiders and predatory beetles. The aim of this research was to assess the effect of cover crop management on the abundance and diversity of ground-dwelling arthropods. For this purpose, a three-year experiment was conducted in a pear orchard that was divided into three blocks with two plots each: one with a sown cover of mixed plants from different families, including Boraginaceae, Asteraceae, Apiaceae, Brassicaceae, and Fabaceae, and the other with no cover, in which any spontaneous plants were periodically removed without using herbicides. The abundance of ground-dwelling arthropods was sampled using pitfall traps. The sown cover increased the overall richness of arthropods. Additionally, spiders from the families Lycosidae and Linyphiidae, as well as beetles from the families Carabidae and Staphylinidae, were more abundant in the sown cover. Conversely, detritivores such as collembolans and beetles from the family Tenebrionidae were less abundant in the cover. The abundance of ants was not affected by the type of cover. The sown cover increased the diversity of arthropods in the crop, as well as the abundance of generalist predators.

Diversity of ground-dwelling arthropods on overburden dumps after coal mining

Technogenic landscapes formed by coal mining are unique model sites for studying primary succession. We studied the formation of arthropod communities on rock dumps at coal mine dump sites of different ages and in natural environments. Using the pitfall traps, 5 classes of arthropods were found, with the domination of Insecta and Arachnida. The species composition for most of the studied groups of invertebrates was determined, the Berger-Parker dominance and Shannon species diversity indices were calculated. It has been established that the colonization of dumps depends not only on the age of recultivated lands, but also on habitat conditions (soil characteristics, vegetation parameters). At the beginning of the succession, dumps are massively populated by small-sized species that are tolerant of extreme conditions and have high dispersal abilities. Further development of vegetation entailed a change in the general structure of the ground-dwelling of arthropods communities. Discriminant analysis showed that the macrofauna of the compared sites differs statistically significantly in the space of discriminant functions. The areas at the foot of the dump and the natural biotope are characterized by the maximum differences; the greatest similarity was found between the young and old dumps. A significant contribution to the overall discrimination is made by the beetles of the families Geotrupidae, Staphylinidae, Elateridae, as well as centipedes (Chilopoda), and terrestrial bugs (Hemiptera). This study showed that communities of ground invertebrates are good indicators for monitoring the restoration of technogenically disturbed lands.

Short-Term Postfire Effects on Ground-Dwelling Arthropods and Soil Attributes in a Semiarid Grassland Ecosystem, Northwestern China

Fire-induced effects on biota activity and diversity, and soil attributes, could have implications for biodiversity conservation and recovery of semiarid grassland ecosystems. Here, we examined the abundance and diversity of ground-dwelling arthropods, and soil attributes in burned and unburned grasslands in the semiarid Nanhuashan Natural Reserve in western Loess Plateau of China. Arthropods and soil were sampled in springtime one year after fire disturbance. We found no significant differences in total abundance of ground-dwelling arthropods between burned and unburned grasslands. However, the taxonomic richness and the Shannon index of ground-dwelling arthropods were found to be significantly greater in burned than unburned grasslands. Postfire effects also indicated significant differences in dominance hierarchy among taxa within functional groups as a consequence of increasing predatory abundance but decreasing phytophagous one from unburned to burned grasslands. Likewise, soil bulk density declined, whereas soil C/N increased significantly from unburned to burned grasslands. In conclusion, fire could promote the taxonomic richness and the diversity of ground-dwelling arthropods, thus being indicators of positive effect of fire disturbance on biodiversity conservation of semiarid grassland ecosystems of northwestern China. However, soil bulk density and soil C/N could be susceptible to fire-driven changes of soil attributes.

Impact of soil fertilization on arthropod abundance and diversity on soybean agroecosystem

Abstract. Hasibuan R, Cindowarni O, Lumbanraja J, Lumbanraja FR. 2022. Impact of soil fertilization on arthropod abundance and diversity on soybean agroecosystem. Biodiversitas 23: 1828-1835. Arthropods are biotic components that play an important role in the ecosystem. The field experiment consisting five fertilizer treatments: 100% NPK, 100% organic fertilizer, 100% NPK and 50% organic fertilizer, 50% NPK and 100% organic fertilizer, and no fertilizer was conducted to study the arthropod abundance and diversity in soybean agroecosystem. Pitfall traps were set up for collecting soil arthropods, while data for foliar arthropods were obtained by visual observation. During the study, the soybean agroecosystem was inhabited by 2756 arthropods that belong to 64 families. The results of arthropod community composition indicated that soil and foliar arthropods were most dominated by Coleoptera and Hemiptera. Predators were the most abundant in pitfall traps and herbivores with a visual inspection. Additionally, predators had the highest number of families. Soil fertilizer treatments had a significant impact on the abundance of foliar arthropods and soil arthropods. The highest numbers of foliar arthropods were found in soybean plants treated by inorganic fertilizer (NPK) either alone or in combination. However, soil arthropods were most abundant in soybean treated by organic fertilizer. The application of organic fertilizers to the soybean agroecosystem was able to increase the diversity of ground-dwelling arthropods and foliage-inhabiting arthropods across sampling periods.

Influence of Weed Management Practices on Ground-dwelling Arthropod Assemblages in Organic and Conventional Apple Orchards

Ground-dwelling arthropods are important components in apple orchard providing beneficial ecological services of predation and decomposition as well as herbivory. Groundcovers are managed differentially in organic and conventional apple orchards influencing ground-dwelling arthropod assemblages. We conducted 3-year studies to assess the effects of orchard management relative to weed management on the abundance and diversity of ground-dwelling arthropods using pitfall trapping. Most arthropods were classified as higher taxonomical groups and functional feeding guilds, while carabid beetles were classified into species level. Coleoptera was the dominating taxon of all ground-dwelling arthropods. Abundance of herbivores and predators was significantly higher in organic apple orchards than conventional ones. Higher abundance and diversity of carabid beetles were found in organic orchards than in conventional orchards. The abundance of Araneae, Coleoptera, or carabid beetles was negatively correlated to weed management frequency. It was found that ground-dwelling arthropods were more influenced by weed management practices than the farming systems.

Mid-elevational Peaks in Diversity of Ground-dwelling Arthropods with High Species Turnover on the Colorado Plateau.

Patterns of biodiversity along elevational gradients elucidate how climate shapes biological communities and help predict ecosystem responses to environmental change. Arid elevational gradients are particularly interesting because temperature limitations at high elevations and precipitation limitations at low elevations cause mid-elevation peaks in diversity. Ground-dwelling arthropods form highly diverse communities but few studies document elevational patterns of their full diversity. Here we investigate the elevational patterns of ground-dwelling arthropods in northern Arizona on the Colorado Plateau, an arid and understudied region in the United States. We sampled seven sites along an elevation gradient from 1,566 to 2,688 m corresponding to a difference of 6.5°C average annual temperature and 620 mm average annual precipitation. We captured 16,942 specimens comprising 169 species, mostly ants and beetles, and discovered a new ant species. First- and second-order elevation terms significantly correlated to multiple measures of arthropod α and β diversity. Arthropod abundance, richness, and Shannon-Wiener diversity index peaked at mid-elevations, with functional groups (i.e., omnivores, predators, detritivores, and herbivores) showing similar patterns. Community composition varied significantly across the gradient, correlated with changes in elevation, and was driven by shifts of ants dominating low- to mid-elevations, to beetles dominating high-elevations. Dissimilarity among sites was driven by high species turnover with 59% of species exclusive to a single site, whereas nestedness among sites was low except at the lowest elevation site. High rates of turnover and elevation-dependent communities suggest that ground-dwelling arthropods are highly vulnerable to environmental change, particularly at lower elevations in arid regions.

The Effect of Cover Crops on the Biodiversity and Abundance of Ground-Dwelling Arthropods in a Mediterranean Pear Orchard

The intensification of agriculture has led to the reduction of the diversity of arthropods in agroecosystems, including that of ground-dwelling species. The aim of our work was to assess the effect of a sown cover crop on the diversity of ground-dwelling arthropods, including key predators for pest control in pear orchards. The trial was carried out in a pear orchard divided in three blocks; two treatments (cover-cropping and control) were implemented in each block. A seed mixture of 10 plant species was used in the plots with the sown cover. The densities of ground-dwelling arthropods were sampled using pitfall traps. The ground cover had a significant impact on the diversity and abundance of arthropods. The Shannon–Wiener diversity index was significantly higher for the cover than for the control plots. Several families of spiders (Linyphiidae, Lycosidae), beetles (Carabidae, Staphylinidae) and hymenopterans (Scelionidae) were significantly more abundant in the cover-sown plots. Ants and collembola had a significantly higher abundance in the control plots. Some of these groups arthropods (ants and spiders), are represented by species that may commute between ground and pear trees, having an impact on pest control. The use of cover crops is encouraged to enhance biodiversity in farmlands.

Composition and diversity of ground-dwelling arthropods at Chiayi Agricultural long-term ecological research site in the Southern Taiwan

In this study, the canola oil and alcohol were used as attractants in pitfall traps to help collect ground-dwelling arthropods. Two small agricultural long-term ecological research fields at Chiayi Agricultural Experimental Station were chosen to execute sampling activities. There were 14,509 individuals of 182 species (including morphospecies) in 18 taxa in the collections. The most abundant taxon was Hymenoptera, followed by Coleoptera, Collembola, Diptera, Orthoptera, and Acari. Regardless to the difference of the sampling fields, canola oil trap was significantly attractive to ants (Formicidae, Hymenoptera). On the other hand, the alcohol trap was more effective in attracting the Coleoptera. According to the diversity analysis, the results indicated that the diversity indexes were affected by the main effect for attractant. In addition, the interactions between the farming operation and samplings and between the attractant and samplings were also factors to influence the diversity of ground-dwelling arthropods in the long-term ecological research site of Chiayi Station.

Gradients in abundance and diversity of ground dwelling arthropods as a function of distance to tree rows in temperate arable agroforestry systems

Ground dwelling arthropods present in agricultural systems regulate multiple ecosystem services (ES), such as nutrient and carbon cycling and biological pest control. The presence of semi-natural landscape features, such as the tree component of agroforestry systems (AFS), can contribute to functional agrobiodiversity and optimize the delivery of such ES in agricultural landscapes. In temperate AFS, however, potential patterns in abundance and diversity have scarcely been investigated for detritivorous soil dwelling arthropods and only to a limited extent for predatory arthropods. Therefore, we have assessed the abundance and diversity of woodlice (Isopoda), millipedes (Diplopoda), rove beetles (Coleoptera: Staphylinidae) and carabids (Coleoptera: Carabidae) as a function of the distance to the tree row in a set of temperate arable AFS. Abundance and diversity of woodlice and millipedes were significantly higher in the tree rows than in the arable zone. In the case of mature trees, a higher abundance of detritivores was also observed in the arable zone close to the trees. Tree presence did not consistently lead to higher abundance of predatory arthropods, but a limited increase in carabid diversity was observed in the arable zone close to the tree rows. These results indicate that in temperate AFS, the trees and the associated understory vegetation strip contribute to the preservation of arthropod biodiversity and the enhancement of associated ES in the tree rows and in the arable field zone.

Reducing management intensity and isolation as promising tools to enhance ground-dwelling arthropod diversity in urban grasslands

Urbanisation is a growing global phenomenon having multiple ecological consequences. However, the effects of urbanisation on biodiversity remain ambiguous, and some evidence exists that cities provide valuable secondary habitats for many species, possibly mitigating regional biodiversity loss. Therefore, the value of urban sites for biodiversity depends on local habitat conditions and the configuration of the surrounding landscape. We aimed to disentangle the effects of local habitat parameters (management, plant diversity) and urban matrix variables (urbanisation, isolation) on carabid beetle and spider diversity and traits in informal urban green spaces in Berlin, Germany. Habitat management and isolation were the most important influences on carabid beetle and spider species and trait compositions. Spider communities of irregular managed sites contained 2.5 times more species of conservation concern than extensive (regular) managed sites. Moreover, irregular managed sites contained larger species (both for carabid beetles and spiders) and affected the hunting mode of spiders. Isolated sites tended to have lower spider species richness and number of spider species of conservation concern. Moreover, isolated sites were characterised by small, mobile and herbivorous carabid beetles. In contrast, urbanisation and local plant diversity had no effect on carabid beetles and spiders. We conclude that urban grasslands within residential areas – even if not targeted for conservation plans – can provide important habitats for conserving biodiversity, including species of conservation concern. Reducing the intensity of habitat management and increasing the connectivity of urban grassland sites can promote diverse arthropod communities and should therefore be considered in urban planning.

Microhabitat heterogeneity promotes soil fertility and ground-dwelling arthropod diversity in Mediterranean wood-pastures

Mediterranean wood-pastures are extensive agroforestry systems that hold great ecological, social and cultural values, which consist of mixtures of grassland, scattered trees and shrubs, primarily used for livestock grazing. For centuries, low-intensity management in these landscapes has resulted in multiple microhabitats that favour biodiversity and are considered key elements for the long-term persistence of wood-pastures. However, the relative contribution of each microhabitat type to wood-pasture biodiversity and functioning remains poorly studied. We investigated the impact that different wood-pasture microhabitats have on soil chemical fertility and the decomposition food web. We analysed the two main microhabitats that make wood-pastures up – open grasslands and isolated trees – and three additional “litter-trapping” microhabitats – shrubs scattered in the grassland matrix, canopied shrubs and piles of pruning debris—in terms of soil chemical properties (organic matter content, total N, C:N ratio, available P, and exchangeable base cations), collembolan and dipteran (mostly detritivores) abundance, and carabid (seed-eaters and predators) and staphylinid (mostly predators) beetle abundance, body size, biomass, species richness and composition. Grasslands were the most different microhabitats, with the lowest soil nutrient content and particular carabid and staphylinid species composition. Trees had the highest soil fertility levels and abundance of Diptera and staphylinids, and held unique staphylinid assemblages. “Litter-trapping” microhabitats had medium to high soil nutrient values and shared a distinct staphylinid assemblage compared to grasslands and trees. Besides, scattered shrubs provided shelter for large-sized carabid and staphylinid predators, while canopied shrubs held the highest carabid abundance and biomass. “Litter-trapping” microhabitats retained tree leaves that would otherwise be lost to the wood-pasture, recovering nutrients to the system, and provided new habitat, shelter and food for detritivores and unique predator assemblages. “Litter-trapping” microhabitats thus enhanced soil fertility and the decomposition process, at the same time as increased the abundance and diversity of the communities of ground-dwelling detritivores and predators inhabiting wood-pastures. These findings confirmed that microhabitat heterogeneity resulting from low-intensity management is essential to maintain both the primary production and the biodiversity conservation value of wood-pastures.

Spinosad and spinetoram disrupt the structure and the abundance of ground-dwelling arthropod communities in herbaceous fields

ABSTRACTIn the present study, the effects of spinosad, spinetoram and chlorpyrifos on ground-dwelling arthropod diversity and abundance were compared in a herbaceous field in order to evaluate their relative compatibility with conservation of arthropod densities. Ten different treatments of spinosad, spinetoram, and chlorpyrifos, which was used as a toxic reference, were allocated at random to experimental plots. A total of 101,119 individuals of epigeal arthropods belonging to 18 orders and suborders were captured in pitfall traps, with the most abundant taxa Hymenoptera, Collembola, Araneae, Acari, Coleoptera, Isopoda, Julida and Opiliones. The orders Araneae, Coleoptera, Collembola, Hymenoptera and Opiliones were identified to the family or species level. Gnaphosidae, Carabidae, Entomobryidae, Formicidae and Metaplatybunus grandissimus CL Koch (Phalangiidae) were the most abundant taxa of Araneae, Coleoptera, Collembola, Hymenoptera and Opiliones, respectively. Significant density reduction was observed for Gnaphosidae, Linyphiidae (Araneae), Carabidae, Entomobryidae, Formicidae and M. grandissimus after chlorpyrifos treatment. Formicidae individuals were significantly reduced after spinosad application, while the Entomobryidae and M. grandissimus individuals were reduced after the application of both spinosad and spinetoram. Our results showed no significant differences in diversity level of orders and suborders as well as of Araneae families between the spinetoram-treated plots at both concentrations tested and the control. In contrast, a significant difference in the diversity of Coleoptera was detected between the spinetoram treatments and the control. Our findings showed that spinosad and spinetoram may disrupt the structure and the abundance of surface-active arthropod fauna causing considerable changes in the ground-dwelling biodiversity of this ecosystem.

Can mixed stands of native and non-native tree species enhance diversity of epigaeic arthropods in plantation forests?

In regions with low cover of natural forests and high cover of plantations predominately comprised of non-native species, inclusion of a native tree species with a more productive non-native species has the potential to enhance biodiversity and meet production goals. In this context, we tested the alternative hypotheses that: (i) equitable mixes of a non-native and a native tree species support greater diversity of ground-dwelling arthropods than single species stands; or, (ii) native ash stands support greater diversity of ground-dwelling arthropods than mixed or single species stands that include a non-native conifer species. Active epigaeic spiders (Araneae) and beetles (Coleoptera: Carabidae, Staphylinidae) were sampled using pitfall traps in three forest types in Ireland: single species stands of non-native Norway spruce (Picea abies) or native ash (Fraxinus excelsior), and mixed stands of these species.Stands of Norway spruce did not negatively influence spider and staphylinid diversity, suggesting that they maintain a similar range of biodiversity to mixed plantations or stands of native ash. However, carabid beetle richness (but not abundance) was negatively affected by the presence of spruce suggesting caution when drawing conclusions about biodiversity impacts from single taxon studies. We found that equitable mixes of spruce and ash supported many species associated with native ash stands. Thus, we recommend that mixes with an equitable species ratio (e.g. 50:50) and containing a native species will enhance epigaeic arthropod diversity and heterogeneity in plantations. Furthermore, our finding that ash stands supported greater beta diversity than spruce stands supports current guidelines that recommend a range of stand types, including native species, to enhance diversity within and between stands.

Changes in ground-dwelling arthropod diversity related to the proximity of shrub cover in a desertified system

Shrub patchiness generates spatial heterogeneity across a range of scales. Little is known about shrub-patch effects on ground-dwelling arthropod diversity on small spatial scales. Using pitfall trapping, ground-dwelling arthropods were collected at three microsites (beneath and on the shrub-canopy periphery, and in open spaces) during spring, summer, and autumn, in a desertified steppe ecosystem of northwestern China. Along with distance from shrub cover, the abundance of dominant groups, including Carabidae, Tenebrionidae, and Glaphyridae families, tended to decrease and was remarkably affected by seasonality, in contrast to the abundance distribution pattern of the dominant Melolonthidae, Curculionidae, and Formicidae families. The distribution pattern of total abundance, group richness, and Fisher's α index among the microsites was also found to be affected by seasonality. Together, the abundance distribution of different dominant taxa was found to indicate distinctive responses to the microsite and seasonal variability. The distribution pattern of the ground-dwelling arthropod community among the microsites could change along with seasonality, though high diversity was found to be maintained beneath the shrub cover. This study elucidated the importance of plant-cover functions as ‘keystone structures’, providing heterogeneous microsite – soil arthropod relationships that altered in time and space in xeric environments.

Survey of Ground Dwelling Arthropods Associated with Two Habitat Types in the Jos Museum Zoological Garden Jos Plateau State, North Central Nigeria

Little is known about the species composition and ecology of ground dwelling arthropods of Zoological Gardens. Thus, this study was aimed to investigate the species abundance and diversity of ground dwelling arthropods associated with Gallery forest and Rocky outcrop of the Jos Museum Zoological Garden Jos Plateau State, North central Nigeria. Arthropods were collected using Pitfall traps during the raining season of June-July, 2013. A total of 500 arthropods belonging to 6 Classes, 11 Orders, 12 Families, 14 Genera and 14 Species were collected. Out of which 130 arthropods individuals representing 26% of the total were collected from Gallery forest, whereas 370 arthropods individual representing 74% were collected from Rocky outcrop. There is a significant difference in the mean abundance of species of ground dwelling arthropods collected from both habitats. There is no significant difference in the mean abundance of ground dwelling arthropods in relation to taxa. The diversity and distribution of arthropods taxa depicted 73% Insecta and 64.4% Hymenoptera as the most abundant taxa. The Shannon-Weiner diversity index (H) differs significantly between the two habitat types. The Gallery forest had the highest diversity index of 2.2140 and Rocky outcrop had the lowest diversity index of 0.9038. Food availability and vegetation cover were found to be critical to arthropods species abundance and diversity. This is a pointer to the usefulness of vegetation and food as key resources for ground dwelling arthropods. It is therefore recommended that adequate protection of the garden be carried out to curd anthropogenic activities. Key Words: Arthropods, Habitats, Gallery forest, Rocky outcrop and Zoological garden

Effect of naturally vs manually managed restoration on ground-dwelling arthropod communities in a desertified region

Both naturally and manually managed restoration can effectively improve degraded ecosystems; however, little is known about the option of restoration management for the recovery of ground-dwelling arthropod communities in desertified regions. Naturally restored grassland (termed here “grassland”) and manually afforested shrubland (termed here “shrubland”) were compared in relation to ground-dwelling arthropod communities; the adjacent mobile sand land was used as a control. Both types of restoration markedly improved soil and herbaceous properties, with the grassland characterized by high plant herbaceous richness and abundance in addition to low soil temperature, and the shrubland characterized by high soil fine-sand content and clay-plus-silt content as well as low coarse-sand content. Restoration management in different habitats resulted in the specific distribution of arthropod groups, with the Labiduridae and Anatolicas (Tenebrionidae) dominant in the mobile sand land and the Formicidae dominant at both restored sites. Total abundance was correlated with the dominant taxa, even for the Simpson index; both were significantly higher in the mobile sand land than in the restored sites, while no significant differences were found between the two types of restoration. Restoration management facilitated ground-dwelling arthropod diversity, including taxon richness, with markedly higher values in the restored sites compared with those in the mobile sand land. Furthermore, taxon richness and Shannon index were noticeable in the shrubland, with significantly higher values than in the grassland. Soil temperature, water content, and bulk density together explained the different structure of ground-dwelling arthropod communities at each site where the restored procedures were implemented. Overall, the manually afforested shrubland was found to contribute much more to the conservation of ground-dwelling arthropod diversity relative to the naturally restored grassland, where both restored strategies were used to facilitate the processes of fixation and recovery of desertified sand land.

Invasive moss alters patterns in life-history traits and functional diversity of spiders and carabids

Invasive plants can modify terrestrial habitats and affect the natural faunal composition. In acidic coastal dunes the invasive moss Campylopus introflexus can form dense carpets that largely replace native vegetation. As shown in a previous study, moss invasion affects habitat structure and ground-dwelling arthropod diversity. We suggested that including the functional diversity concept in the analysis of moss invasion impacts may offer further insights. We used pitfall trap data to compare trait composition and functional diversity of spiders and carabids in (a) invaded, moss-rich (C. introflexus) and (b) native, lichen-rich (Cladonia spp.) acidic coastal dunes. Moss invasion induced shifts in the trait values body size and feeding preference (carabids) and hunting mode (spiders): Species were smaller in native sites, and the percentages of web-building spiders and phytophagous beetles were reduced in invaded sites. Furthermore, moss invasion led to a more heterogeneous trait composition for spiders, and changed functional diversity of both arthropod groups, although with the opposite effects: While spiders were functionally more diverse in invaded sites, moss invasion reduced carabid beetles’ functional diversity. We also observed changes in the relationship between species richness and functional diversity that indicate a high functional similarity for spiders but a lower one for carabid beetles in native grey dunes. C. introflexus invasion not only alters the arthropod diversity and assemblage structure of endangered acidic coastal dunes but also interferes at a functional level. These results provide further insight into the way plant invasions might alter the structure and function of ecosystems.

Shrubs and species identity effects on the distribution and diversity of ground-dwelling arthropods in a Gobi desert

Disentangling the relationship between shrub vegetation and ground-dwelling arthropods at multiple levels of taxonomic resolution is essential to developing a suitable management strategy for the conservation of shrub-associated arthropod biodiversity in shrubland ecosystems. Using Gobi desert (dominated by shrub species Nitraria sphaerocarpa and Reaumuria soongorica) occurring widely in inland arid areas of northwest China as a model system, we sampled ground-dwelling arthropods by pitfall trapping method under canopies of both shrubs and in intershrub bare areas during spring, summer and autumn. Our aim was to determine whether the presence and species identity of shrubs influence the distribution of ground-dwelling arthropods and whether the influence of shrub presence and species identity differs among trophic and taxonomic groups. At the community level, total arthropod abundance and species richness were significantly greater under shrubs than in intershrub bare habitats, whereas more arthropods were captured under N. sphaerocarpa than under R. soongorica. At the trophic group level, the abundance of predator and decomposer arthropods was significantly greater under shrubs than in intershrub bare habitats, whereas herbivore and decomposer arthropods were more abundant under N. sphaerocarpa than under R. soongorica. At the family level, the abundance of Carabidae, Gnaphosidae, Karschiidae, Tenebrionidae and Thomisidae was consistently much greater under shrubs than in intershrub bare habitats, whereas that of Formicidae, Philodromidae and Tettigoniidae did not differ between the shrub microhabitats and the intershrub bare habitats. However, the abundance of Curculionidae under R. soongorica and the abundance of Geotrupidae under N. sphaerocarpa were significantly lower than that in intershrub bare habitats. N. sphaerocarpa was commonly preferred by arthropods in the families of Curculionidae and Tenebrionidae, whereas R. soongorica was commonly preferred by arthropods in the family Geotrupidae, but shrub species identity did not affect the abundance of the remaining families. Our results suggest that shrubs and species identity play important roles in structuring ground-dwelling arthropod communities, but the response of arthropods differed among trophic or taxonomic groups. This study may have important implications for the conservation of invertebrate biodiversity in Gobi desert ecosystems.

The impact of forest ski-pistes on diversity of ground-dwelling arthropods and small mammals in the Alps

Forest clearing for winter sport activities is the major force driving loss and fragmentation of the alpine forests. The establishment of ski-pistes involves impacts on every ecosystem component. To assess the extent of this threat we studied ground-dwelling arthropods (namely ground beetles and spiders) and small mammals (shrews and voles) at two ski resorts in north-western Italian Alps by pitfall trapping. Diversity parameters (mean abundance, species richness and Shannon index) of spiders and macropterous carabids increased from forest interior to open habitats (i.e., ski-piste or pasture), whereas parameters of brachypterous carabids significantly decreased from forest interior to open habitats. Diversity parameters of macropterous ground beetles were higher on pastures than on ski-pistes. Small mammals were virtually absent from ski-pistes. Observed frequencies in the three adjacent habitats were significantly different from expected ones for the bank vole Myodes glareolus and the pygmy shrew Sorex minutus. Generalized linear models showed that abundance, species richness and diversity of spiders and macropterous carabids of ski-pistes were best modelled by combination of factors, including grass cover and width of the ski-piste. Indicator Species Analysis showed that species that significantly preferred ski-pistes were less than those preferring pastures, and species which were exclusive of ski-pistes were very few. To retain arthropod ground-dwelling fauna of open habitats environmentally friendly ways of constructing pistes should be developed. After tree clearing, only the roughest ground surfaces should be levelled, in order to preserve as much natural vegetation as possible. Where necessary, ski-pistes should be restored through the recovery of local vegetation.